Tong Zhong-chun, Ni Long-xing, Ma Li-fang, Zhou Lin, Hou Bo, Zhao Xiu
Dept. of Conservative Dentistry, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2009 Aug;27(4):386-9.
To construct luxS mutant aften luxS gene of Streptococcus mutans (S. mutans) was knocked out, and examine their ability of biofilm formation.
A recombinant plasmid containing the flanking fragment of luxS of S. mutans was transformed into S. mutans UA159, and selected by brain heart infusion (BHI) agar medium with kanamicin. The luxS mutant further confirmed via polymerase chain reaction (PCR) and the autoinducer-2 (AI-2) bioluminescence assay of Vibrio harveyi (V. harveyi), and ability of luxS mutant and S. mutans UA159 biofilm formation was examined in different phases, in BHI medium with 1% sucrose and 1% glycose by scanning electron microscopy (SEM).
LuxS-deficient S. mutans strains were successfully constructed. Compared with S. mutans UA159, the luxS mutant maintained in BHI medium containing 1% sucrose displayed an apparent defect in biofilm formation, while they showed no significant deviation in BHI medium containing 1% glycose.
luxS gene in S.mutans can play a role in dental plaque biofilm formation, and the luxS gene is possible to regulate sucrose-dependent biofilm formation.
构建变形链球菌（S. mutans）luxS基因敲除后的luxS突变体，并检测其生物膜形成能力。
将含有变形链球菌luxS侧翼片段的重组质粒转化至变形链球菌UA159中，并用含卡那霉素的脑心浸液（BHI）琼脂培养基进行筛选。通过聚合酶链反应（PCR）及哈维氏弧菌（V. harveyi）的自诱导物-2（AI-2）生物发光测定进一步确认luxS突变体，并通过扫描电子显微镜（SEM）在含1%蔗糖和1%葡萄糖的BHI培养基中检测luxS突变体和变形链球菌UA159在不同阶段的生物膜形成能力。
成功构建了luxS缺陷型变形链球菌菌株。与变形链球菌UA159相比，在含1%蔗糖的BHI培养基中培养的luxS突变体在生物膜形成方面表现出明显缺陷，而在含1%葡萄糖的BHI培养基中则无显著差异。
变形链球菌中的luxS基因可在牙菌斑生物膜形成中发挥作用，且luxS基因可能调控依赖蔗糖的生物膜形成。
